Many of these once-hot names are lovely, even classic. They’re just not as stylish as they once were (although some, especially from the earlier decades, are on their way back in).

We looked at the Top 25 baby names for each decade of the 20th century to pick out choices that were hot back them, and are not today. Included here are Old People Names like Bertha and Clarence, Baby Boomer names such as Karen and Gary, today’s mom and dad names such as Jennifer and Jason, and names like Taylor and Tyler that are beginning to be heard much more often on babysitters than on babies.

Yes, there are baby names that have had longer runs at the top of the popularity list. Mary and John, certainly, and, more recently, Michael, who ruled for 44 years, yet none of them came to be seen as an epidemic or to signify a whole generation in the way that Jennifer did, though she was Number 1 for a mere fifteen years.

But in that time, between 1970 and 1984, there were 859,112 little Jennifers born in the US—enough for online Jennifer identity-loss support groups to spring up as they matured, enough for future parents to bemoan “I don’t want my child to be one of five named Jennifer in her class,” and enough for us to call our first book Beyond Jennifer and Jason. Jennifer became a one-girl baby names trend.

But why Jennifer? A once obscure Cornish form of the old Welsh Gwenhwyfar, aka Guinevere, a name that was hardly heard here before 1938—except for an appearance in a 1905 Shaw play– and which didn’t enter the Top 100 till 1956.

There’s a new generation of mom names, not the midcentury Kathys and Sues that are fast becoming grandma names, but the names of young moms today, born for the most part in the 70s and 80s, their names acquiring a more grownup image as they’ve grown up themselves.

This blog was inspired by the discussion of mom names over on the forums. On that board, berries are discussing their own moms’ names plus the names of moms they know who have young children.

Of course, not every name of a twenty-or-thirty-something mother qualifies as a mom name. What does?

Yesterday we took a look at the girls’ names moving in and out of fashion and now we turn our attention to their brothers.

And here we find a somewhat different picture.

Overall, it confirms the fact that there is much greater consistency on the boys’ side of the fence, with a huge proportion of the names already established in the Top 100 list of 1880, and very few new ones entering in the succeeding years: only one or two per decade, with a large number of them having Irish roots.